Brown Pants moment

N

NMC100

Member
 Cotswolds / London
Had a bit of an eventful easter weekend in the M. Started with an awesome blast up to the parents in the countryshire on thursday night, driving the roads I know so well from my teenage years in my old BL Mini Cooper. Then yesterday some inconsiderate tit in a beaten up van forced me into a rather large pot hole on a narrow lane - luckily I had anticipated his Toad of Toad Hall antics and pretty much reached a standstill as I crashed through the hole and ploughed the verge with the lower corner of my bumper. :evil:

The 'highlight' however was the big moment I had on the M25 last night. Around junction 19 I hit some standing water at legal motorway speeds in the outside lane. Cue big fishtails for around 50 meters. I was pretty sure I was going to take some corners off against the concrete central res. The chap next to me must have thought I was taking him out as well. Somehow after 3 or 4 big swings it righted. Needless to say I was quickly in the nearside lane thanking my lucky stars. The unerving thing was I wasn't pushing on, the rain wasn't too bad, tyres are 5mm all round and I was completely taken by surprise. :?
Maybe it's time to ditch the Conti's for some PSs.
 
Re the M25 - I drove there last night in the Polo as well, and unfortunately like most roads in the UK the design is so bad that water is standing on the surface rather than run off. Even at 50 mph I was often "floating".
 
Only one bit of the M25 has a decent stretch of self draining surface. Ironically it's not the bit that has been recently relaid or widened!
 
First rain after a few dry days or weeks washes up all the oil, which then sits on the top as a thin greasy film. :evil:

Always beware of the first rain after a long hot or hot spell ! :thumbsup:
 
Glad you and the zed are ok. For all the bad press the TV test pilots give nanny TC electronics, it's saved me twice in similar standing water situations , massive fish tails followed by omg how did it do that :)

The contis are ok Until you need to change them... Just don't turn off the TC :driving:
 
Glad it all worked out in the end. Just to throw in what I think about aquaplaning, it really is something that should be taught properly and covered as part of the test. My knowledge and data comes from aircraft wheels but, unless someone can correct me, I believe the principle is the same for cars.

Empirically, the speed at which an unbraked wheel aquaplanes is dependant upon pressure. Weight, tyre size, contact area etc. don't seem to matter. Once a tyre has fully aquaplaned there is nothing that can be done until it regains contact with the road surface so don't think that any traction aids will help. They might stop the wheel or maybe keep it rolling but can't gain traction when a complete layer of water is present between the road and tyre. They might help in the partial stages though.

The data I have gives the following info, with standing water it's probably a good idea to drop down to 55 or less.

Pressure Speed
(PSI) (MPH)

30 54.21
31 55.10
32 55.98
33 56.85
34 57.71
35 58.55
36 59.38
37 60.20
38 61.01
39 61.80
40 62.59
 
@NMC100

Glad the M and you are still intact. This car still scares me but havent had any moments like yours.....yet... :evil:
 
Scooba_Steve said:
Glad it all worked out in the end. Just to throw in what I think about aquaplaning, it really is something that should be taught properly and covered as part of the test. My knowledge and data comes from aircraft wheels but, unless someone can correct me, I believe the principle is the same for cars.

Empirically, the speed at which an unbraked wheel aquaplanes is dependant upon pressure. Weight, tyre size, contact area etc. don't seem to matter. Once a tyre has fully aquaplaned there is nothing that can be done until it regains contact with the road surface so don't think that any traction aids will help. They might stop the wheel or maybe keep it rolling but can't gain traction when a complete layer of water is present between the road and tyre. They might help in the partial stages though.

The data I have gives the following info, with standing water it's probably a good idea to drop down to 55 or less.

Pressure Speed
(PSI) (MPH)

30 54.21
31 55.10
32 55.98
33 56.85
34 57.71
35 58.55
36 59.38
37 60.20
38 61.01
39 61.80
40 62.59
Click to expand...

PS, regarding my comment on the traction control / DSC, obviously during the moment of aquaplaning you can't do anything, however, once the tyres get back onto tarmac contact, with the car already at 30degree slip angle and the tyres beginning to obtain grip with road speed differential and still whlist still travelling forward at 50-60mph, I believe it is the DSC that helps to correct itself into straight line... I certainly don't think that has anything to do with my driving skills :P
 
@Fast3000 - Thanks - this was my first such moment in nearly a year of ownership. I used to hate driving my Elise in the wet as it aquaplaned so easily. Up until last night the M has been very planted.

@Sae - the DSC certainly corrected the fishtailing impressively. I was a passenger at that point. Glad I had it on for once.

Gotta love the ///M! :driving:
 
The rain was a nightmare!

I drove back from Towcester near Silverstone yesterday afternoon in the pouring rain and a couple of times on the M40 and M25 (where it wasn't as wet) the car (E92 320d) was all over the place.

Roads were very greasy and slippery!

Like you, tyres are all fine, was driving well under the speed limit due to the spray and it was still being silly lol.
 
It was extremely greasy yesterday, suspect a combination of being dry for a good while and pollutants. My car was very mucky again after the rain has dried off.
 
You must log in or register to reply here.
Back
Top Bottom